Design and Investigation of Four Low Solidity Vaned Diffusers to Assess the Effect of Solidity and Vane Number

Abstract

As part of a continued effort to understand the design and performance of Low Solidity Vaned Diffusers (LSVD), four new LSVDs have been designed and tested. A centrifugal compressor stage usually consists of the inlet, impeller, diffuser and collector systems. Even though the individual components of the compressor are capable of achieving high efficiency, it is the efficiency of the whole stage that is of great importance. The diffuser system of a centrifugal compressor comes basically in two general categories either as vaneless or vaned diffuser (excluding pipe diffusers). Vaned diffusers can further be subdivided into two depending on channel geometry as straight channel or curved channel, or depending on solidity. It is currently believed that the LSVD offers a compromise between a vaned and a vaneless diffuser by possessing the virtues of each. This paper discusses the design and experimental investigation of the new four LSVDs. The diffusers had a solidity of 0.9, 0.8, 0.7 and 0.6. These newly designed LSVDs are known as LSVD#5 to LSVD#8.